The present invention relates to a device for and a method of measuring a tensile force in a reinforcing member in reinforced concrete, particularly prestressed reinforced concrete.
Prestressed reinforced concrete includes hardened cement paste, stone aggregates, and reinforcing members such as steel bars or strands which have been prestressed. The hardened mixture of the cement paste and aggregates offers excellent resistance to compressive stresses, but only low resistance to tensile stresses. Therefore the reinforcing members are embedded in the concrete in such areas that develop tensile stresses due to the superimposed loads on the structure. Methods of computations are known, which allow the design engineers to size structural members, such as beams, columns, slabs, etc. and allocate suitable amounts of steel reinforcement. There are situations when an engineer must determine the stress that prevails in the reinforcing steel elements in the existing structures. However, there are no methods and devices for performing such determinations.